<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        var number=219347924;
        //var t = String.fromCharCode(99);
        //显示c
        //var t = "abcdefgabcdefg123".lastIndexOf("abc");
        var t = "abcdefgabcdefg123abcdefgabcdefg123"
        //显示最后一次出现括号内的字符的位置，可循环
        var r = /a[a-zA-Z]c/gi;
        //正则表达式
        var h = /1(39|50|36){8}/gi;
        //alert(t);
        alert(t.replace(r,"*"));
    </script>
</body>
</html>